1. Field of the Invention
This invention relates to a light source device for an endoscope, and more particularly to a light source device for an endoscope, incorporating a lamp for supplying the light to a light guide fiber bundle for the illumination of the endoscope.
2. Description of the Prior Art
As has been well known, the endoscope is widely used for observing the interior of a space, which is difficult to be observed from outside, in the medical and industrial fields. Most of the endoscopes are of such an arrangement that the light for the illumination necessary for the observation is obtained from the light of a lamp in an external light source device via a light guide fiber bundle for the illumination. Furthermore, in general, in the light guide fiber bundle for the illumination, a light inciding end portion (a side opposed to the lamp) is fixedly bundled by use of a bonding agent or the like and inserted into and solidly secured to a tubular protective sheath so as to be inserted into and connected to a connector on the side of the light source device. However, the light guide fiber bundle for the illumination thus arranged present such disadvantages that the bonding agent may be highly heated by radiant heat from the lamp and burned out, or, when the light guide fiber bundle for the illumination is removed from the connector, an operator may have a burn because the tubular protective sheath is considerably highly heated by the heat of the lamp.
Therefore, to obviate the above-described disadvantages, there has been proposed a light source device for an endoscope provided with heat radiating means.
For example, in the specification of Japanese Patent Publication No. 23067/65, there is disclosed heat radiating means, in which a light inciding end portion of the light guide fiber bundle for the illumination is formed into a flat shape, and this flat-shaped light inciding end portion is clamped by radiator plates from both sides to thereby radiate the heat of the light guide fiber bundle. Furthermore, in the specification of Japanese Patent Laid-Open No. 204009/82, heat radiating means, in which a heating portion of a heat pipe consisting of the heating portion, a heat transmitting portion and a heat radiating portion is brought into contact with a side surface of a light inciding end portion of the light guide fiber bundle for the illumination, to thereby lower the temperature of the light inciding end portion. Further, in the specification of Japanese Utility Model Laid-Open No. 158206/81, there is disclosed heat radiating means, in which radiator fins are provided on a socket on the side of the light source device, to which the light guide fiber bundle is connected, to thereby lower the temperature of the light guide fiber bundle.
Notwithstanding, in the heat radiating means disclosed in the aforesaid specifications, the contact between the light guide fiber bundle and the heat radiating means is unsatisfactory so that a satisfactory radiating effect cannot be obtained. More specifically, if even a small gap is formed between the light guide fiber bundle for the illumination and the heat radiating means, then no effective heat transmission is carried out from the light guide fiber bundle to the heat radiating means such as the radiator fins, so that a satisfactory heat radiating effect cannot be obtained.